U.S. patent application number 12/412003 was filed with the patent office on 2009-10-01 for exhaust gas turbocharger for a motor vehicle.
Invention is credited to Markus Eble, Andreas Wengert.
Application Number | 20090246005 12/412003 |
Document ID | / |
Family ID | 41010914 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090246005 |
Kind Code |
A1 |
Eble; Markus ; et
al. |
October 1, 2009 |
EXHAUST GAS TURBOCHARGER FOR A MOTOR VEHICLE
Abstract
The present invention relates to an exhaust gas turbocharger for
a motor vehicle, comprising a turbine housing having a first area
in which exhaust is carried to a turbine wheel and in which the
turbine wheel is essentially situated and having a second area
connected axially to the first area, such that the first area and
the second area are essentially separated from one another by a
separating element. It is provided that for thermal insulation, the
separating element (14) is made of a material having a low thermal
conduction (24) and/or thermal capacity.
Inventors: |
Eble; Markus; (Stuttgart,
DE) ; Wengert; Andreas; (Auenwald, DE) |
Correspondence
Address: |
RADER, FISHMAN & GRAUER PLLC
39533 WOODWARD AVENUE, SUITE 140
BLOOMFIELD HILLS
MI
48304-0610
US
|
Family ID: |
41010914 |
Appl. No.: |
12/412003 |
Filed: |
March 26, 2009 |
Current U.S.
Class: |
415/170.1 ;
415/177 |
Current CPC
Class: |
F02B 37/00 20130101;
F05D 2300/5024 20130101; F02B 39/00 20130101; F01D 25/14 20130101;
Y02T 10/144 20130101; F01D 17/165 20130101; Y02T 10/12 20130101;
F05D 2220/40 20130101; F05D 2300/21 20130101 |
Class at
Publication: |
415/170.1 ;
415/177 |
International
Class: |
F01D 11/00 20060101
F01D011/00; F01D 25/08 20060101 F01D025/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2008 |
DE |
102008000852.4 |
Claims
1. An exhaust gas turbocharger for a motor vehicle, comprising: a
turbine wheel; a separating element; a turbine housing having a
first area, in which exhaust is carried to the turbine wheel and in
which the turbine wheel is essentially arranged, and having a
second area connected axially to the first area such that the first
area and the second area are separated from one another by the
separating element and wherein the separating element is
constructed from a material including at least one of a low thermal
expansion and a thermal capacity for thermal insulation such that
the separating element reduces heat transfer from the first area to
at least one of the second area and the turbine wheel.
2. The exhaust gas turbocharger as recited in claim 1, wherein the
separating element constructed from a ceramic based material.
3. The exhaust gas turbocharger as recited in claim 1, wherein the
separating element constructed from of a carbon fiber material
based material (CFK).
4. The exhaust gas turbocharger as recited in claim 1, wherein the
separating element is inserted into a bearing element.
5. The exhaust gas turbocharger as recited in claim 1, wherein the
separating element is inserted into a receptacle of a bearing
element.
6. The exhaust gas turbocharger as recited in claim 1, wherein the
separating element is forced by at least one spring into a
receptacle of a bearing element.
7. The exhaust gas turbocharger as recited in claim 6, wherein the
spring is a plate spring.
8. The exhaust gas turbocharger as recited in claim 6, wherein the
spring is supported at one end on the separating element and at the
other end on a bearing housing for supporting the turbine
wheel.
9. The exhaust gas turbocharger as recited in claim 2, wherein the
separating element is inserted into a bearing element.
10. The exhaust gas turbocharger as recited in claim 2, wherein the
separating element is inserted into a receptacle of a bearing
element.
11. The exhaust gas turbocharger as recited in claim 2, wherein the
separating element is forced by at least one spring into a
receptacle of a bearing element.
12. The exhaust gas turbocharger as recited in claim 11, wherein
the spring is a plate spring.
13. The exhaust gas turbocharger as recited in claim 11, wherein
the spring is supported at one end on the separating element and at
the other end on a bearing housing for supporting the turbine
wheel.
14. The exhaust gas turbocharger as recited in claim 3, wherein the
separating element is inserted into a bearing element.
15. The exhaust gas turbocharger as recited in claim 3, wherein the
separating element is inserted into a receptacle of a bearing
element.
16. The exhaust gas turbocharger as recited in claim 3, wherein the
separating element is forced by at least one spring into a
receptacle of a bearing element.
17. The exhaust gas turbocharger as recited in claim 16, wherein
the spring is a plate spring.
18. The exhaust gas turbocharger as recited in claim 16, wherein
the spring is supported at one end on the separating element and at
the other end on a bearing housing for supporting the turbine
wheel.
19. The exhaust gas turbocharger as recited in claim 4, wherein the
separating element is inserted into a receptacle of a bearing
element.
20. The exhaust gas turbocharger as recited in claim 4, wherein the
separating element is forced by at least one spring into a
receptacle of a bearing element.
Description
[0001] The present invention relates to an exhaust gas turbocharger
for a motor vehicle, comprising a turbine housing having a first
area in which exhaust gas is carried to a turbine wheel and in
which the turbine wheel is essentially situated, and having a
second area which follows the first area axially such that the
first area and the second area are essentially separated from one
another by means of a separating element.
BACKGROUND INFORMATION
[0002] To increase the performance of internal combustion engines
in motor vehicles, it is known that exhaust gas turbochargers are
to be used. Exhaust gas from the internal combustion engine is
supplied to a turbine wheel mounted in a turbine housing. The
turbine wheel is mounted on a shaft on which a compressor wheel of
a compressor is mounted in a rotationally fixed manner at an axial
distance from the turbine wheel. As a rule, the turbine housing has
at least two areas, a first area of which serves to supply exhaust
gas to the turbine wheel and a second area serves to hold an
adjustment mimicking mechanism of a guide vane arrangement with an
adjustable turbine geometry and/or to hold a bearing for the shaft.
The areas are separated from one another by a separating element,
which serves in the prior art to center a cassette, for example,
which holds the guide vane arrangement of the variable turbine
geometry. The separating element here is designed as a disk and is
arranged behind from the turbine wheel (in the axial direction
toward the compressor). During operation of the exhaust gas
turbocharger, the turbine wheel reaches temperatures of 900.degree.
C. in conventional diesel internal combustion engines and up to
1110.degree. C. in conventional gasoline engines. In this way, the
separating element is subject to a substantial thermal burden on
the one hand, while on the other hand, a substantial quantity of
heat is input into the turbine housing and/or into the second area
via the separating element.
[0003] The object of the present invention is to provide an exhaust
gas turbocharger for a motor vehicle that avoids the aforementioned
disadvantages.
SUMMARY OF THE INVENTION
[0004] An exhaust gas turbocharger for a motor vehicle is proposed
here, comprising a turbine housing having a first area in which
exhaust gas is supplied to a turbine wheel, in which the turbine
wheel is essentially situated and which has a second area connected
to the first area axially, such that the first area and the second
area are separated from one another essentially by a separating
element. It is proposed that the separating element for thermal
insulation should be made of a material having a low thermal
conduction and/or thermal capacity. This achieves the result that
unlike arrangements known in the prior art in which the separating
element is made of a metal, in particular steel, the separating
element, does not deliver the thermal energy absorbed by the hot
exhaust gas and/or by the hot turbine wheel to the elements acted
upon or adjacent thereto, e.g., the turbine housing, not by direct
thermal conduction or by radiant emission after absorbing heat
itself (because the thermal capacity should be low according to the
present invention). The separating element consequently effectively
prevents a transfer of heat from the first area into the second
area and/or into areas which are acted upon by the separating
element and are not directly acted upon by the hot exhaust gas or
are in direct proximity to the hot turbine wheel.
[0005] The separating element is preferably made of ceramic.
Ceramic is a known insulation material and has a very high heat
resistance but can also be manufactured industrially very
advantageously in mass production.
[0006] In another embodiment, the separating element is preferably
made of a carbon fiber material (CFK, carbon fiber-reinforced
material). This material also allows a very good thermal insulation
with a high strength.
[0007] In both variants, i.e., in the ceramic embodiment or the CFK
embodiment, for example, the thermal expansion can be adjusted
through a suitable choice of materials of the separating element,
i.e., adjustment of the respective material parameters, as well as
the surrounding components, e.g., the turbine housing. This
achieves the result that the thermal behavior of the bearing
housing, for example, does not deviate from that of the separating
element to such an extent that unwanted phenomena must be expected
because of differences in thermal expansion during operation.
[0008] In another embodiment, the separating element is inserted
into a bearing element. The bearing element here is, for example, a
bearing that serves to support the separating element, i.e., to
hold it so that it does not come in direct contact with the turbine
housing.
[0009] The separating element is preferably inserted into a
receptacle in the bearing element, i.e., a receptacle or geometric
arrangement which allows the introduction of the separating
element. The bearing element may in turn create a plurality of
(additional) bearings, e.g., that of the shaft, that of the
separating element or other elements of the exhaust gas
turbocharger, or it may be dedicated entirely to just the bearing
of the separating element.
[0010] In another embodiment, the separating element is forced by
means of at least one spring into the receptacle of the bearing
element. In order for the separating element to remain secured in
the receptacle of the bearing element after being introduced into
the desired position, it is provided that a spring force acts, such
that the spring is supported on the separating element on one end
and on a suitable supporting surface on the other end, so that the
separating element remains held in the receptacle by the spring
force.
[0011] The spring is especially preferably a plate spring. A plate
spring can be designed in a ring, e.g., in a design that saves on
design space in particular and can be accommodated between the
bearing element and the variable turbine geometry in the design
space.
[0012] It is preferably provided that the spring is supported on
the separating element on one end and on a bearing housing for
supporting the turbine wheel on the other end. Consequently, the
turbine wheel has a bearing housing into which a shaft bearing, for
example, is introduced for its support. This bearing housing has
supporting surfaces on which the spring is supported on the one end
while it is also supported on the separating element on the other
end and thus its spring force acts between the supporting surfaces
on the bearing housing and the separating element.
[0013] Additional advantageous embodiments are derived from the
dependent claims and from combinations thereof; the figure shows
details.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention is described in greater detail below
on the basis of one exemplary embodiment although it is not limited
to that.
[0015] The FIGURE shows a section at the height of the shaft
through a turbine housing of an exhaust gas turbocharger with the
separating element inserted.
EMBODIMENT(S) OF THE INVENTION
[0016] The FIGURE shows an exhaust gas turbocharger 1 for an
internal combustion engine (not shown) of a motor vehicle (not
shown) in an axial sectional view at the level of a shaft 2, namely
at the level of a turbine axis 3 of a turbine wheel 4. The exhaust
gas turbocharger 1 has a turbine housing 5, in the first area 6 of
which exhaust gas is carried to the turbine wheel 4, in which the
exhaust gas guides 7 introduced into the turbine housing 5 for the
oncoming flow of exhaust gas to the turbine wheel 4 run, and in
which the turbine wheel 4 is essentially arranged. The turbine
housing 5 also has a second area 8, which is connected axially to
the first area and in which a control mimicking mechanism 9 is
provided for controlling a variable turbine geometry 10 such that
the variable turbine geometry 10 is arranged in the first area 6
and produces the oncoming flow to the turbine wheel 4 with the
exhaust gas entering from the exhaust gas guide 7. A bearing
housing 11 is also situated in the second area 8 for support of the
shaft 2 and the turbine wheel 4, which is in turn supported in the
manner of a cover in an internal circumferential area 12 of an end
face 13 of the turbine housing 5 and through which the shaft 2
passes. Between the bearing housing 11 and the turbine wheel 4 is
provided a separating element 14 which is exposed to an axial end
face 15 of the bearing housing 11, which faces the turbine wheel 4
on the outside circumference and is in turn supported in a bearing
element 16 of a cover plate 17 of the variable turbine geometry 10
in the dividing plane 18 between the first area 6 and the second
area 8. The bearing element 16 is designed in the form of a ring
and surrounds the turbine wheel 4 at one end. It has a receptacle
19 in the form of a peripheral bearing edge 20 with a ring-shaped
recess (having essentially an L shape 21 in cross section), such
that the receptacle is open with respect to the bearing housing 11,
whereas it is designed to be closed with respect to the turbine
wheel 4. The separating element 14 is situated in the L shape 21 of
the receptacle 19, where it is held by a spring 22, namely a plate
spring 23, which is in turn supported on the separating element 14
at one end and on the bearing housing 11 on the other end. The
separating element 14 here is made of a material having a low
thermal conduction 24, in particular ceramic 25 or a carbon fiber
material 26 (CFK). In this way, a heat transfer from the first area
6 to the second area 8 with an oncoming flow of hot exhaust gases
to the turbine wheel 4 and/or from the turbine wheel 4 is very
effectively reduced or largely prevented with only short-term
operation. At the same time, this prevents an unwanted transfer of
heat to the bearing housing 11.
* * * * *